[GSBN] Straw Bale Insulated Ceiling
John Swearingen
jswearingen at skillful-means.com
Tue Feb 4 18:38:24 UTC 2014
Jorge, in this case, the membrane was applied directly to the plaster on
the bales. We used a liquid-applied latex membrane which had at least a
little vapor permeability...
The area gets about 12 cm of rain per year (4.7 in), spread more or less
equally through 7-8 months, in short, intense storms, so the curved roof
sheds the water quickly and can easily dry in the dry desert air after the
storm. I would hesitate to do this in an area with lingering, wetting,
storms.
John
On Tue, Feb 4, 2014 at 9:36 AM, Van Krieken <vankrieken at gmail.com> wrote:
> John
>
> On the vault roof, was there any ventilation on the top of the roof, so
> that the air introduce from the bottom could go out in the top?
> Was there a ventilatiion space between the vault "walls/roof" and the
> outside roof?
>
> I allways wanted to make one vault --. just experimenting -- and I welcome
> all info and tips on the subject.
>
> Regarding your question, yes, its wood slats on the ceiling.
>
> All the best
>
> Jorge Van Krieken
> Portugal
>
>
>
>
> On Tue, Feb 4, 2014 at 4:54 PM, John Swearingen <
> jswearingen at skillful-means.com> wrote:
>
>> For the "igloo" method, we did do a bale vault in the desert. One source
>> of concern we had was about vapor being able to escape to the outside,
>> since the latex roof membrane was directly on the bales. After plastering,
>> the bales contained a lot of moisture, and the house wasn't occupied, and
>> with the building at an equilibrium with the outside temperature, little
>> drying was happening, and we went running to Dr. Straube for advice. He
>> suggested we turn on the air conditioning, and that created enough
>> temperature differential to drive the vapor to the outside. I'm not sure I
>> would do a roof anywhere but the desert without some sort of venting at the
>> top of the bales.
>>
>> An interesting feature we noted in our monitoring was that the vapor
>> moved around in the bales in the vault quite a bit following the heat of
>> the sun. We've observed this in walls, as well--vapor moves freely around
>> inside the bales following temperature conditions, particularly from the
>> sun. One thing this means is that if you have a condensing surface at the
>> top of the bales (often the case), and a source of excessive moisture (air
>> leak), heat will drive vapor to the top of the wall where it may condense
>> and cause damage.
>>
>> Nice bulidings, Jorge. On the first house, what's the ceiling? It looks
>> like wood slats...
>>
>> John "I go Igloo" Swearingen
>>
>>
>> On Tue, Feb 4, 2014 at 6:45 AM, Van Krieken <vankrieken at gmail.com> wrote:
>>
>>> Feile
>>>
>>>
>>> 1. As well as in the walls, the gaps bettween the bales on the roof have
>>> to be carefully closed with loose straw. Its a easy task, but it takes time
>>> to be really well done (as everything else, I guess! :-)
>>>
>>> 2. When you put the bales on the roof (and afterwords the top wood
>>> structure) you'll notice that its not really very flat (as the walls
>>> aren't), so, if you just plaster it you'll find many places with 5, 6, 7 or
>>> even more cm of plaster. Thats very heavy. This is one of the reasons I
>>> prefer to use LECA mixed with the lime (just enought to agregate the LECA),
>>> because we can put 5, 6 or more cm without a height problem. I do not thing
>>> you need to put it on the bottom side of the bales, the ones in contact
>>> with the OSB, but before puting the bales I spray OSB and bales with a
>>> generous borax dilution, let it well dry and then put the bales. You may
>>> also wanto to use a special anti-fire OSB in the roof.
>>>
>>> 3. The fllor. because we need thermal mass, we use a 20 cm limecreet
>>> (stones, 1/2 lime and 1/2 cement). Then 5 or 6 cm of sand mixed with 50%
>>> lime and 50% white cement (just a little water on it). When is still fresh,
>>> we apply the powder: white cement and natural ochre with a tiny little bit
>>> of red (iron sulphate). In that particular case we used 700 g white cement
>>> + 150 g ochre + 10 g of red. After, you should apply some wax or natural
>>> vernish (we use form www.ecospaints.com ). Thats it.
>>>
>>> I like the "igloo" method (complete surrounded by insulation) to make
>>> a house. Its looks to me that is much more easy and fast, and with no
>>> thermal leeks. We are also building several houses with cork, using the
>>> same "Igloo" procedure. You may see one here (we have build this one in 12
>>> days, 6 persons (140 m2).
>>>
>>> http://www.queridacasa.com
>>>
>>>
>>> Hope you enjoy! All the best
>>>
>>> Jorge Van Krieken
>>> Portugal
>>>
>>>
>>>
>>> l
>>>
>>> On Tue, Feb 4, 2014 at 10:35 AM, Feile Butler <feile at mudandwood.com>wrote:
>>>
>>>> Thanks to all of you for your replies
>>>>
>>>> Danny and Jorge - you both mention the difficulty in packing the gaps
>>>> between bales effectively. I suspected that might be a problem - so good to
>>>> get your practical experience in the field.
>>>>
>>>> You both also say that sealing with plaster is the best way to achieve
>>>> fire rating. Bohdan mentioned a fire test from Germany - does anyone know
>>>> who the author is so that I could look it up? Or does anyone have
>>>> information on thicknesses of plaster required to achieve various fire
>>>> ratings?
>>>>
>>>> Bohdan - I understand why you are questioning why they don't just use a
>>>> natural fibre batt. I think a big part of the reason is ethos. The clients
>>>> have access to plenty of locallly produced straw bales - which are as close
>>>> to an unprocessed but effective insulation product as they can get. I
>>>> suppose another option would be to look at accessing and cleaning a load of
>>>> sheep fleeces. But if that is not an option - then they need to buy a
>>>> manufactured product. Only sheep's wool is produced in Ireland (which would
>>>> be a good option), but it is manufactured in the exact opposite corner of
>>>> the country. Anything else (wood fibre, hemp) would have to be imported
>>>> from Europe.
>>>>
>>>> But, as you say, if we end up using an excessive amount of timber to
>>>> support the bales, then that is not a truly sustainable solution either.
>>>> It's always a balancing act! As I said in the previous email - we're
>>>> just exploring the option at the moment.
>>>>
>>>> Jorge - I thought that was interesting that you used the LECA with the
>>>> lime - I presume you did it to have achieve the maximum insulation values.
>>>> But with an entire bale doing the job for you, do you think that was an
>>>> excessive detail? Or was there another reason I missed?
>>>>
>>>> I also have to say I LOVED the look of the house when it was entirely
>>>> enclosed with bales - great to see bale walls AND roof.
>>>>
>>>> And as an aside - I love the colour of the floor too, particularly the
>>>> yellow. Was that an earth floor? Did you have very pale earth on the site
>>>> and pigment it up with ochre? It's a really beautiful finish.
>>>>
>>>> Cheers
>>>>
>>>> Feile
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> ----- Original Message -----
>>>> *From:* Van Krieken <vankrieken at gmail.com>
>>>> *To:* Global Straw Building Network <GSBN at sustainablesources.com>
>>>> *Sent:* Monday, February 03, 2014 10:44 PM
>>>> *Subject:* Re: [GSBN] Straw Bale Insulated Ceiling
>>>>
>>>> I used strawbales in the roof, with a special atention to fill the
>>>> voids between the bales (its quite time consuming). We sealed the bales
>>>> with a hidrated (or aerial) natural lime mixed with expanded clay
>>>> aggregate.
>>>> You may see some pictures here: http://strawhouses.carbonmade.com
>>>>
>>>> All the best
>>>>
>>>> Jorge Van Krieken
>>>> Portugal
>>>>
>>>>
>>>> On Mon, Feb 3, 2014 at 4:09 PM, Danny Buck <dannycbuck at msn.com> wrote:
>>>>
>>>>> Our experience here in New Mexico was that the roof structure gave
>>>>> us a lot of voids between bales that were very challenging to pack. If it
>>>>> is a true attic with a flat open surface to work off of, that would be
>>>>> different.
>>>>>
>>>>> The surface of the bale that is accessible to air (oxygen) is best
>>>>> sealed with a plaster.
>>>>>
>>>>> Danny Buck
>>>>> Daniel Buck Construction, Inc.
>>>>>
>>>>> ----- Original Message -----
>>>>> *From:* Feile Butler <feile at mudandwood.com>
>>>>> *To:* Global Straw Building Network <GSBN at sustainablesources.com>
>>>>> *Sent:* Monday, February 03, 2014 2:57 AM
>>>>> *Subject:* [GSBN] Straw Bale Insulated Ceiling
>>>>>
>>>>> Hi All
>>>>>
>>>>> I have clients who are considering insulating above the ceiling with
>>>>> straw bales. They have a large attic which could easily accommodate the
>>>>> bales and plenty of outbuildings, so they don't need the attic for storage.
>>>>>
>>>>> I have never detailed a straw bale ceiling before, but would like to
>>>>> explore the idea.
>>>>>
>>>>> One of my main concerns is fire. Is it enough to encapsulate the
>>>>> bales within plasterboard/clayboard on both sides (top and bottom)? If we
>>>>> want to deck out the floor above the bales, would it be enough to coat them
>>>>> in a lime or earth plaster before building up the floor above them? Is
>>>>> there any data out there about the behaviour of straw bales in ceilings
>>>>> that I can show the building control officer, particularly with regard to
>>>>> fire?
>>>>>
>>>>> Any advice on or experience of straw bale insulated ceilings would be
>>>>> very welcome.
>>>>>
>>>>>
>>>>> Thanks
>>>>>
>>>>>
>>>>> *Féile Butler*
>>>>>
>>>>> *MRIAI B.Arch Dip. Arch Conservation Grade III*
>>>>>
>>>>> *Mud and Wood*
>>>>>
>>>>> *Grange Beg, Skreen, **Co. Sligo, Ireland*
>>>>>
>>>>>
>>>>>
>>>>> *T:
>>>>> +353 (0) 71 930 0488 <%2B353%20%280%29%2071%20930%200488>*
>>>>>
>>>>> *M: +353 (0) 86 806 8382 <%2B353%20%280%29%2086%20806%208382>*
>>>>>
>>>>> *E : **feile at mudandwood.com*
>>>>>
>>>>> *W:www.mudandwood.com*
>>>>> _______________________________________________
>>>>> GSBN mailing list
>>>>> GSBN at sustainablesources.com
>>>>> http://sustainablesources.com/mailman/listinfo.cgi/GSBN
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> GSBN mailing list
>>>>> GSBN at sustainablesources.com
>>>>> http://sustainablesources.com/mailman/listinfo.cgi/GSBN
>>>>>
>>>>>
>>>> ------------------------------
>>>>
>>>> _______________________________________________
>>>> GSBN mailing list
>>>> GSBN at sustainablesources.com
>>>> http://sustainablesources.com/mailman/listinfo.cgi/GSBN
>>>>
>>>>
>>>> _______________________________________________
>>>> GSBN mailing list
>>>> GSBN at sustainablesources.com
>>>> http://sustainablesources.com/mailman/listinfo.cgi/GSBN
>>>>
>>>>
>>>
>>> _______________________________________________
>>> GSBN mailing list
>>> GSBN at sustainablesources.com
>>> http://sustainablesources.com/mailman/listinfo.cgi/GSBN
>>>
>>>
>>
>>
>> --
>> John Swearingen
>> Skillful Means Design & Construction
>> 2550 9th Street Suite 209A
>> Berkeley, CA 94710
>> 510.849.1800 phone
>> 510.849.1900 fax
>>
>> Web Site: http://www.skillful-means.com
>> Blog: https://skillfulmeansdesign.wordpress.com
>>
>> _______________________________________________
>> GSBN mailing list
>> GSBN at sustainablesources.com
>> http://sustainablesources.com/mailman/listinfo.cgi/GSBN
>>
>>
>
> _______________________________________________
> GSBN mailing list
> GSBN at sustainablesources.com
> http://sustainablesources.com/mailman/listinfo.cgi/GSBN
>
>
--
John Swearingen
Skillful Means Design & Construction
2550 9th Street Suite 209A
Berkeley, CA 94710
510.849.1800 phone
510.849.1900 fax
Web Site: http://www.skillful-means.com
Blog: https://skillfulmeansdesign.wordpress.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.sustainablesources.com/pipermail/gsbn/attachments/20140204/0215c1f9/attachment.htm>
More information about the GSBN
mailing list